Re: pthread_cond_timedwait

["Scott Lightner" <scott@curriculum.com>]

_ftime() will give you the current time with milliseconds.

I believe struct timespec is in nanoseconds so you will lose some precision.

Scott
----- Original Message -----
From: <Mikael.Ambrus@elema.siemens.se>
To: <pthreads-win32@sourceware.cygnus.com>
Sent: Thursday, September 09, 1999 11:47 AM
Subject: pthread_cond_timedwait


> [Ambrus Mikael]  Dear pthreads colleagues,
>
> I'm writing a program that uses pthread_cond_timedwait. In the book
> that I'm using (Pthreads Programming by Nicols, Buttlar & Proulux Farell )
> it says that this function should suspend the thread until some other
thread
> calls  pthread_cond_signal, pthread_cond_broadcast OR the system timer is
> greater than or equal to the third argument (abstime).
>
> Since clock_gettime is not implemented and I cant find some other
> function that tells me the system time, I've tried to implement my own
> version of clock_gettime by using the ansi function clock(). This function
> returns the number of ticks that has elapsed since the program was
started.
>
> But it seams that this is not the same absolute time that
> pthread_cond_timedwait requires since the thread won't awaken.
>
> Is there another way to acquire the relevant system time?
>
> Another thing that has bothered me is that I recently downloaded the
> latest snip of phtreads and now my read/write locks won't work. Since the
> precompiled lib isn't recognised by the linker (neither with gcc v20.1 nor
> MSVC 6.0) for some reason, I built the libs using the buildlib.bat
provided.
> Here's a snip of the code that fails:
>
> int pthread_rdwr_wunlock_np (
>    pthread_rdwr_t *rdwrp
> ){
>    assert( pthread_mutex_lock(&(rdwrp->mutex)) == 0 );
>    if (rdwrp->writers_writing == 0) {
>       assert( pthread_mutex_unlock(&(rdwrp->mutex)) == 0 );
>       return(-1);
>    }else{
>       rdwrp->writers_writing = 0;
>       assert(pthread_cond_broadcast(&(rdwrp->lock_free)) == 0);
>
>    };
>
>    assert( pthread_mutex_unlock(&(rdwrp->mutex)) == 0 );
>    return(0);
> };
>
> pthread_cond_broadcast returns EINVAL. Does anyone recognise this
> problem?
>
> Wkr
> Michael Ambrus
> Siemens Elema
> >
>